SLES10 Fixes (part 6)

- Prior to 2.6.17 there were no *_pgdat helper functions in mm/mmzone.c.
  Instead for_each_zone() operated directly on pgdat_list which may or
  may not have been exported depending on how your kernel was compiled.
  Now new configure checks determine if you have the helpers or not, and
  if the needed symbols are exported.  If they are not exported then they
  are dynamically aquired at runtime by kallsyms_lookup_name().
This commit is contained in:
Brian Behlendorf
2009-05-20 14:23:13 -07:00
parent 3731931529
commit 5232d256b4
6 changed files with 157 additions and 23 deletions
+38
View File
@@ -802,6 +802,31 @@ AC_DEFUN([SPL_AC_GET_VMALLOC_INFO], [
[])
])
dnl #
dnl # 2.6.17 API change
dnl # The helper functions first_online_pgdat(), next_online_pgdat(), and
dnl # next_zone() are introduced to simplify for_each_zone(). These symbols
dnl # were exported in 2.6.17 for use by modules which was consistent with
dnl # the previous implementation of for_each_zone(). From 2.6.18 - 2.6.19
dnl # the symbols were exported as 'unused', and by 2.6.20 they exports
dnl # were dropped entirely leaving modules no way to directly iterate over
dnl # the zone list. Because we need access to the zone helpers we check
dnl # if the kernel contains the old or new implementation. Then we check
dnl # to see if the symbols we need for each version are available. If they
dnl # are not, dynamically aquire the addresses with kallsyms_lookup_name().
dnl #
AC_DEFUN([SPL_AC_PGDAT_HELPERS], [
AC_MSG_CHECKING([whether symbol *_pgdat exist])
grep -q -E 'first_online_pgdat' $LINUX/include/linux/mmzone.h 2>/dev/null
rc=$?
if test $rc -eq 0; then
AC_MSG_RESULT([yes])
AC_DEFINE(HAVE_PGDAT_HELPERS, 1, [pgdat helpers are available])
else
AC_MSG_RESULT([no])
fi
])
dnl #
dnl # Proposed API change,
dnl # This symbol is not available in stock kernels. You may build a
@@ -850,6 +875,19 @@ AC_DEFUN([SPL_AC_NEXT_ZONE], [
[])
])
dnl #
dnl # 2.6.17 API change,
dnl # See SPL_AC_PGDAT_HELPERS for details.
dnl #
AC_DEFUN([SPL_AC_PGDAT_LIST], [
SPL_CHECK_SYMBOL_EXPORT(
[pgdat_list],
[],
[AC_DEFINE(HAVE_PGDAT_LIST, 1,
[pgdat_list is available])],
[])
])
dnl #
dnl # Proposed API change,
dnl # This symbol is not available in stock kernels. You may build a